UMass Amherst food scientist Hang Xiao is investigating mechanisms that enable bioactive compounds in our food to reduce the risk of chronic disease. His work shows special promise in preventing colon cancer—America’s second leading cause of cancer death.

Xiao was recently granted the prestigious International Life Sciences Institute (ILSI) Future Leader Award coupled with $30,000 in funding. He is using the grant to explore ways to increase bioavailability (the extent and rate to which things can be absorbed by the body) of bioactive components in food, thus maximize their health benefits. Xiao explains that the degree to which these compounds can have health-promoting effects depends largely on the human body’s ability to absorb and deliver them to areas where they are needed. Too often, the body excretes these compounds before they can have the most desirable effect.

Xiao is paying particular attention to polymethoxyflavones (PMFs)—a unique class of flavonoids almost exclusively found in citrus fruits. According to Xiao, PMFs can reduce inflammation in the body, most noticeably in the colon.

“The reason why it’s unique for the colon is that there is a direct exposure to the active compounds in the colon—our body is producing them on site,” says Xiao.

In fact, the body processes PMFs differently than many other flavonoids. After ingestion, PMFs are absorbed and sent from the small intestine to the liver, where they are metabolized to conjugates – substances that are more water-soluble. These conjugates are sent back to the small intestine via bile secretion. When these conjugates travel through the small intestine and into the large intestine, the microorganisms that live in our digestive tract called “gut micro flora”, convert them into an array of potent anti-inflammatory compounds. As a result, a considerable amount of highly active anti-inflammatory agents are released into the colon, an area vulnerable to chronic inflammation-associated disease such as Crohn’s disease, colitis and cancer.

Within the greater context of one of the best food science programs of the country, Xiao has worked closely with David Julian McClements and Eric Decker over the past several years to investigate the processes of digestion and absorption of food components. The collaborative group is developing ways to encapsulate bioactive food components and target their release throughout the digestive tract using various delivery systems such as nanoemulsions—combinations of two liquids with nanoscale particles of one liquid suspended in the other. If successfully translated, the benefits exhibited by PMFs and other compounds could be realized in different parts of human bodies.

Xiao’s awarded funding from the ILSI, plus support from the National Institutes of Health and the American Institute for Cancer Research, has allowed him to build on the collaborative efforts of the department. The group also recently received a $490,000 grant from a US Department of Agriculture and EPA joint program to further develop the nanoemulsion delivery system. Xiao and his colleagues must ensure that by increasing the potency of bioactive food components they are not unleashing any harmful effects.

“We want to make sure our delivery system is safe to be consumed… it’s food, not a drug. We don’t tolerate any toxicity in food,” says Xiao.

Xiao moved from China to the US to continue his education and career, and touts the traditional Chinese adage “food can be the medicine” as the basis for his research interest in diet-based strategies for disease-prevention.

University Relations

Xiao is paying particular attention to polymethoxyflavones (PMFs)—a unique class of flavonoids almost exclusively found in citrus fruits that can reduce inflammation in the body.